Chapter 3 Theory Of Operation - Brother MFC-8220 Service Manual

3.2.2 For Parallel Interface Cable Users
(For Windows
3.2.3 For Windows NT
3.2.4 For Optional NC-9100h Network Interface Users
(For Windows
3.2.5 For USB Interface Cable Users (For Mac
3.2.6 For USB Interface Cable Users (For Mac OS
3.2.7 For Optional NC-9100h Network Interface Users (For Mac OS
3.2.8 For Optional NC-9100h Network Interface Users
(For Mac OS

CHAPTER 3 THEORY OF OPERATION................................................. 3-1

1. ELECTRONICS ...................................................................................................... 3-1
1.1 General Block Diagram .................................................................................................... 3-1
1.2 Main PCB Block Diagram ................................................................................................. 3-2
1.3 Main PCB ......................................................................................................................... 3-3
1.3.1 CPU.....................................................................................................................................3-3
1.3.2 USB .....................................................................................................................................3-4
1.3.3 IEEE 1284 ...........................................................................................................................3-4
1.3.4 ROM ....................................................................................................................................3-5
1.3.5 Flash ROM ..........................................................................................................................3-6
1.3.6 SDRAM ...............................................................................................................................3-6
1.3.7 Optional RAM ......................................................................................................................3-7
1.3.8 EEPROM.............................................................................................................................3-7
1.3.9 Reset circuit ........................................................................................................................3-8
1.3.10 Engine I/O ...........................................................................................................................3-8
1.3.11 Panel I/O .............................................................................................................................3-8
1.3.12 Video I/O .............................................................................................................................3-8
1.3.13 Scanner control ...................................................................................................................3-9
1.3.14 Power supply.......................................................................................................................3-9
1.4 Engine PCB .................................................................................................................... 3-10
1.5 Power Supply.................................................................................................................. 3-11
1.5.1 Low-voltage power supply.................................................................................................3-11
1.5.2 High-voltage power supply ................................................................................................3-12
2. MECHANICS ........................................................................................................ 3-13
2.1 Overview of Printing Mechanism .................................................................................... 3-13
2.2 Scanner Mechanism....................................................................................................... 3-14
2.2.1 Document feeding and ejecting mechanism .....................................................................3-14
2.2.2 Scanner.............................................................................................................................3-14
2.3 Paper Transfer ............................................................................................................... 3-15
2.3.1 Paper supply .....................................................................................................................3-15
2.3.2 Paper registration..............................................................................................................3-15
2.3.3 Paper eject ........................................................................................................................3-16
2.4 Sensors .......................................................................................................................... 3-17
2.4.1 Document cover sensors ..................................................................................................3-17
2.4.2 Toner sensors ...................................................................................................................3-17
2.4.3 Cassette sensor / Paper empty sensor .............................................................................3-18
2.4.4 Paper eject sensor ............................................................................................................3-18
2.4.5 Document front sensor / Document rear sensor ...............................................................3-19
2.4.6 Regist sensor ....................................................................................................................3-19
®
95/98/98SE/Me/2000 Professional/XP) ...................................................2-18
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Workstation Version 4.0 Users ............................................................2-23
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95/98/98SE/Me/NT/2000 Professional/XP) ..............................................2-25
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®
X 10.1/10.2.1 or greater Users).................................................................2-31
iii
OS 8.6 to 9.2 Users) ......................................2-28
®
X 10.1/10.2.1 or greater Users) ...............2-29
®
8.6 to 9.2 Users) ...........2-30
MFC-8220
SERVICE MANUAL